The invention relates to a device for actuating at least one throttle valve of an internal-combustion engine, having an actuating device, such as a throttle twist grip, a stop, which may be swiveled about an axis via the actuating device, a driving device corresponding with the stop, and a throttle valve, which may be swiveled by means of the driving device. The stop limits a movement of the throttle valve in an opening direction. The stop is acted upon by a spring in the closing direction of the throttle valve. The driving device follows the stop while being acted-upon by the spring. An adjusting device is provided for a controlled throttle valve intervention.
Actuating devices of this type permit a throttle valve intervention in the closing direction superimposed upon the driver's actuation intention. In this context, reference is made to German Patent document DE 40 11 182 A1.
For example, in the case of a motorcycle, when the throttle twist grip is operated by the driver, a swiveling of a cable pulley takes place by way of a Bowden cable, which cable pulley has a stop, which can be swiveled by means of the cable either indirectly or directly. Acted upon by spring force, the cable pulley is prestressed in the closing direction. If required, by the use of additional kinematic transmission members, the stop corresponds with a driving device and actuates a throttle valve in the opening direction, which throttle valve is arranged on a shaft.
If the throttle twist grip is not operated or is operated less, the cable pulley, while being acted upon by spring force, swivels in the closing direction into the corresponding position defined by the driver. The driving device—also while being acted upon by a spring force—following the stop.
According to a control device, a throttle valve intervention takes place as a function of a plurality of input values in that an adjusting device acts upon the throttle valve in the closing direction. In this case, the driving device lifts off the stop, so that the intervention is not noticeable on the driver side at the throttle twist grip.
Such a throttle valve intervention can take place, for example, with respect to a limiting of the maximal vehicle speed, of the internal-combustion engine torque or, for reasons of acoustics, also before the background of an optimized load cycle.
However, it was found that the uncoupling of the stop and the driving device is problematic, particularly in the lower load range. In the case of small throttle valve angles, a good apportioning capability is required, which does not exist because the driving device follows the stop only slightly because of the spring force and, particularly in the lower load range, the throttle valve is extremely loaded by low pressure.
An aspect of the invention is to cost-effectively provide an actuating device of the above-mentioned type by the use of simple devices, which actuating device is operationally reliable and permits a good apportioning of the internal-combustion engine power also in a lower load range.
This present invention meets this need by providing a device for actuating at least one throttle valve of an internal-combustion engine. The device includes an actuating device, such as a throttle twist grip, a stop, which may be swiveled about an axis by use of the actuating device, a driving device corresponding with the stop, and a throttle valve, which may be swiveled by use of the driving device. The stop limits movement of the throttle valve in the opening direction, and is acted upon by a spring in the closing direction of the throttle valve. The driving device follows the stop while being acted-upon by the spring. An adjusting device is provided for the controlled throttle valve intervention, wherein the stop and the driving device may be mutually coupled in a form-locking manner. According to the basic idea, the stop and the driving device can be formlockingly coupled with one another.
Particularly preferable embodiments and further developments of the invention are described and claimed herein.
According to a particularly preferable embodiment, a coupling of the stop and the driving device takes place as a function of the throttle valve opening angle. That is, below a predetermined throttle valve opening angle (in the case of small throttle valve opening angles), the stop and the driving device are mutually coupled and, above the predetermined throttle valve opening angle (in the case of small throttle valve opening angles), the stop and the driving device are uncoupled.
In an embodiment in which the stop is assigned to a cable pulley, which may be operated by way of a Bowden cable, the Bowden cable covers a partial circumference of the cable pulley, and the driving device is arranged to be axially spaced from the cable pulley. A lever element is expediently provided for connecting the cable pulley and the driving device. The lever element may be operated by means of the Bowden cable. If required, more than a partial circumference of the cable pulley may also be covered by the Bowden cable. It is important that the Bowden cable lifts tangentially off the cable pulley in a transition area. The driving device operates a shaft arranged coaxially with respect to the cable pulley axis.
It is very advantageous for the lever element to be assigned to the cable pulley and to be swivel able together with the latter about the cable pulley axis.
According to a particularly preferable embodiment of the invention, the lever element has a first cable-pulley side end area and a second driving-device-side end area. Expediently, the first end area of the lever element, as a function of the position of the cable pulley, is assigned to the partial circumference of the cable pulley, which is covered by the Bowden cable or is not covered by the Bowden cable.
Advantageously, in the covered partial circumference of the cable pulley, the Bowden cable acts upon the first end area of the lever element such that the lever element is operated in the engaging direction, the second end area being connected with the driving device. In the uncovered partial circumference of the cable pulley, the first end area of the lever element is released, so that the lever element is disengaged while being acted upon by spring force.
The driving device expediently has a recess corresponding with the second end area of the lever element, for the form-locking connection with the lever element.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.